Offshore power plant

ABSTRACT

Platform for a power plant equipped for producing oil and made of reinforced concrete to reduce maintenance cost, consisting of at least one module. Each module will consist of at least one circular column surrounded by concrete to create a desired outer surface. Any of the columns can be used to store the petroleum (oil, gas, production water, sand, etc.), act as expansion chamber(s) and act as passive ballast or separation tank. The platform will have at least one deck for oil producing equipment, at least one deck for a power plant, and will have equipment necessary for electric power distribution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is an U.S. national phase application under 35 U.S.C.§371 based upon co-pending International Application No.PCT/NO2006/000345 filed on Oct. 6, 2006. Additionally, this U.S.national phase application claims the benefit of priority of co-pendingInternational Application No. PCT/NO2006/000345 filed on Oct. 6, 2006.The entire disclosures of the prior applications are incorporated hereinby reference. The international application was published on Apr. 10,2008 under Publication No. WO 2008/041856.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a platform which produce electricpower, more specific an oil or/and gas producing platform holding itsown power plant on one of its upper decks.

2. Description of the Prior Art

Productions of hydrocarbons (oil and gas) is normally done throughconcepts consisting of platforms either floating or standing on theseabed or by use of special purpose built ships.

Today power plants are positioned onshore with a fuel supply from ahydrocarbon source. This source could be either through a pipeline froma platform or it could be from a hydrocarbon storage facility nearby.The energy generated by the power plant is then transported across apower energy network to the end user.

One of the negative aspects of power plants using hydrocarbon fuel todayis the CO2 outlets through the exhaust. Today it is known that CO2 gasinfluence the weather and temperature and thus a threat to theenvironment. The handing of CO2 has become an expensive and difficulttask to clean before the exhaust fumes can be let out into the air.Furthermore, it is very expensive to transport hydrocarbons from an oilproducing facility offshore to an onshore facility either throughpermanent pipelines or by vessel and thus contribute considerably to thecost of producing electric power using hydrocarbons.

SUMMARY OF THE INVENTION

Thus, the main objective with present invention is to provide anoffshore platform which is constructed with an eye to reduce the cost oftransporting hydrocarbons on shore and getting rid of C O2 gas withoutadding it to the atmosphere and causing further environmental problems.This is achieved with the platform according to present invention as itis defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those setforth above will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the annexed drawings wherein:

FIG. 1 is a cross section of a separate module.

FIG. 2 is a horizontal cross section of a completed platform.

FIG. 3 is a vertical cross section A-A of the platform showing thecircular columns partly filled with oil or ballast.

FIG. 4 is a block diagram of an additional process on the platform whichwill be carried out in connection with the power plant.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1, 2, 3 and 4. A platform 10 according to theinvention will consist of a circle of modules 1, each module consistingof at least one of circular column 2, with the same or different size ofdiameter, surrounded by concrete to create a desired outer surface. Thestraight sides 3, 4 of the module will have an angle [alpha] given bythe number of modules 1 the platform 10 shall consist of and thus givingthe size of the platform. The modules will be held together by somefixing means, like bolts or similar. The internal circular “column” 5generated by the modules 1 in the middle of the platform 10 can beeither sealed at the bottom and be used for storage of oil, gas, etc. ornothing, or completely filled with the water surrounding the platform.The modules may be put together in a sealing way so that the centralspace of the platform can be utilized as desired. The production of amodule 1 is based on the Norwegian patent 162 255 for building bridgessubmerged in water (fresh or sea water). The Norwegian patent 162 255describes a method for producing these circular columns 2 in a rationaland economical way. However, the method is not essential for the endresult, so other methods available can be used. When all the modules 1have been produced and put in place to create the complete platform 10,it is then taken offshore, positioned and either lowered down to theseabed on top of one or more production wells for oil and or gas,anchored in position like a floating vessel/platform, or “tied” downlike a tension-leg platform.

The production of this type of platform 10 is much cheaper than themethod used for known platforms like a Condeep where the use of asliding frame which is moved in the vertical direction which results ina higher cost and more difficult process of providing concrete at asteady pace. The known techniques for such sliding frames require highlevel of man power compared to the technique described in the Norwegianpatent 162 255.

As the modules 1 are produced they are simply turned 90[deg.] into avertical position and put in the respective radial position until theplatform 10 has reached its final dimension/size.

Some of the advantages with this type of platform relative to the knownconcepts utilized today are, a) expansion chambers (i.e. one of thecircular columns 2) can be utilized in stead of a flare system, b) theinternal volume of the platform makes it possible to utilize passiveseparation for separation of production water, and c) through thevertical circular columns 2 it can be carried out dry drilling (i.e. notsubsea/subwater drilling) which reduces the danger for uncontrolledblowouts. Any leakage in or collapse of one or more of the circularcolumns 2 will not necessarily be critical for the platform 10 when itcomes to lack of buoyancy etc., because of the number of circularcolumns 2 the platform 10 consist of.

On at least one of the deck 6 to the platform 10 there will be aprocessing plant adapted to the type of hydrocarbons being produced, inaddition to the power plant. The oil and/or gas which normally wouldhave been transported either by a vessel or by a pipeline to an oilrefinery/storage facility onshore will now be fed to an onboard storagetank. This storage tank could be at least one or more of the verticalcircular columns 2. When the oil/gas are placed in one or more of thesecolumns at a high temperature, a natural horizontal separation will takeplace in that or those columns 2, hereafter referred to as theseparation tank 12.

The different quality of hydrocarbon will be used for specific enginessuitable for that type of fuel. The engines will drive a generator toproduce electric power. In the separation tank 12 will sand and/ordebris 13 be taken out and deposited. Any water from the production,production water 14, will be drained out and used for reinjection 24.The power production can be carried out by use of different type ofengines 18. However to simplify the description we have only describedthe process by use of diesel engines, but the process would be the samewith the use of other types of engines.

With reference to FIG. 4. Oil and/or gas 11 from the oil well areallowed to separate in the separation tank 12. Sand/debris 13 andproduction water 14 is taken out from the separation tank 12. Theseparated oil and gas 15 is lead to the process plant 16 on the platformfor production of fuels which are stored in the fuel tanks 17. The fuelfor the diesel engines will be taken from the fuel tank and supplied tothe diesel engines 18. The diesel engine cooling water 19 and exhaustgas 20 will be used to heat up the production water 14. When the exhaustgas have been through a dry filter 21 to remove debris, the exhaust gas20 and the production water 14 are put under high pressure by acompressor 22 for injection 24. By adding the exhaust gas 20 and thetemperature transfer 23 from the cooling water 19 of the diesel engine18 to the production water 14 will combined create very high efficiencywhen injected back into the reservoir. The advantage with this method isthat the mixture of water and oil remnants 14 together with the exhaustgas 20 which include CO2, having a high temperature, will betterdissolve the oil and gas within the reservoir when injected.

However, the most important reason for returning the exhaust gas 20 isthat it would be deposited in its entirety at a low cost and thewithdrawal from the reservoir will be increased. This process isfeasible because the present invention has a very large storagecapacity. No other platform today has this opportunity.

Another advantage with the present invention is that there exists noneed for transportation of the hydrocarbons to an onshore facility,either through pipelines or by use of vessels. The distribution networkfor electric power is much cheaper to install and do not hold such athreat environmental pollution as a pipeline or vessel do.

1-8. (canceled)
 9. A platform system for an oil or gas producing powerplant, said platform comprising: at least one module, said modulecomprising at least one circular column surrounded by concrete to createa desired outer surface; and at least one deck positionable on saidmodule and adapted to support oil producing equipment; wherein saidcolumn being adapted to store therein a fluid from a reservoir and actas a passive separation tank.
 10. The platform as set forth in claim 9,wherein said module comprising a plurality of circular columns eachhaving a different diameter.
 11. The platform as set forth in claim 10,wherein said platform system comprising a plurality of modules, whereinadjacent modules being attachable to each other radially and sealed toform an internal circular column.
 12. The platform as set forth in claim11, wherein said internal circular column being sealed at its bottom andadapted to store a fluid therein.
 13. The platform as set forth in claim10, wherein said fluid stored in at least one of said circular columnsis seawater which is adapted to provide desirable buoyancy and stabilityfor said platform based on weight distribution.
 14. The platform as setforth in claim 13, wherein at least one of said circular columns is anexpansion chamber to cater for variable production pressure from saidfluid.
 15. The platform as set forth in claim 14, wherein at least oneof said circular columns is a storage tank for production water.
 16. Theplatform as set forth in claim 15 further comprising a power plantlocatable on said deck, said power plant being at least one engine. 17.The platform as set forth in claim 16 further comprising a fuel tank.18. The platform as set forth in claim 16, further comprising acompressor adapted to inject said production water and said exhaust intosaid reservoir by pressure.
 19. The platform as set forth in claim 18,wherein said production water and said exhaust injected into saidreservoir are treated with 15000 Hz to produce an emulsion adapted todissolve said fluid in said reservoir.
 20. The platform as set forth inclaim 18 further comprising a dry filter adapted to remove debris fromsaid exhaust.
 21. A power plant platform system comprising: a pluralityof modules radially attachable and sealed to each other to form aninternal circular column, each of said modules comprising a plurality ofcircular columns surrounded by concrete to create a desired outersurface; at least one deck positionable on said modules and adapted tosupport oil producing equipment; a power plant locatable on said deck,said power plant comprising at least one engine and at least one fueltank in fluid communication with said engine; a compressor adapted toinject production water and exhaust from said engine into an oilreservoir; a dry filter adapted to remove debris from said exhaust;wherein at least one of said columns being adapted to store therein afluid from said oil reservoir and act as a passive separation tank;wherein at least one of said circular columns being adapted to storeseawater to provide desirable buoyancy and stability for said powerplant platform system based on weight distribution; wherein at least oneof said circular columns being an expansion chamber to cater forvariable production pressure from said fluid; wherein at least one ofsaid circular columns being a storage tank for said production water.22. The platform as set forth in claim 21, wherein said circular columnsof each of said modules each having a different diameter.
 23. A methodof using a power plant platform system, said method comprising the stepsof: (a) providing a power plant platform system comprising. modulesincluding circular columns surrounded by concrete to create a desiredouter surface; and at least one deck positionable on said modules andadapted to support oil producing equipment; wherein at least one of saidcolumns is a separation tank, and at least one of said columns is anexpansion chamber; (b) transferring fluid from a reservoir into saidseparation tank and separating said fluid in said separation tank intooil and gas, production water, and debris; (c) transferring said oil andgas from said separation tank to a process plant; (d) transferring saidproduction water from said separation tank to a temperature transfer;(e) producing fuel in said process plant from said oil and gas; (f)supplying said fuel to at least one engine located on said deck; (g)heating said production water in said temperature transfer using coolingwater and exhaust from said engine; and (h) injecting said productionwater heated by said temperature transfer and a portion of said exhaustback into said reservoir to increase the dissolving of said fluid insaid reservoir.
 24. The platform as set forth in claim 22 furthercomprising the step, before step (b), of storing seawater in at leastone of said circular columns to provide desirable buoyancy and stabilityfor said power plant platform system based on weight distribution. 25.The platform as set forth in claim 22 further comprising the step,before step (f), of transferring said fuel to at least one fuel tank forsupplying said fuel to said engine.
 26. The platform as set forth inclaim 22 further comprising the step, before step (e), of transferringsaid debris out from said separation tank, and the step of, before step(h), removing debris from said exhaust using a dry filter.
 27. Theplatform as set forth in claim 22 further comprising the step, beforestep (h), of treating said production water and said exhaust with 15000Hz to produce an emulsion adapted to dissolve said fluid in saidreservoir.
 28. The platform as set forth in claim 22 further comprisingthe step, before step (h), of increasing the production life of saidreservoir by adding said exhaust and said production water back intosaid reservoir.